What Is The Appropriate Platy Water Temp? Complete Care Tips

When it comes to popular pet fishes, not mentioning platies is a crime! They are famous for their gorgeous tails and colorful skins, which would be such a wonderful sight for your household tanks. Unfortunately, some people do not pay enough attention to factors that could affect their growth – and the water temp is one of them!

So what is the platy water temp, and are there any efficient tips to ensure their proper development? Our article will gladly dive into those issues, answering all your questions. Do not hesitate to click and scroll down for more verdicts! 

What Is The Appropriate Platy Water Temp?

The Appropriate Platy Water Temp

Here is a fact we need to remind you of: platies are tropical freshwater creatures. What does that mean? It means they can only thrive best in environments with warm temperatures! According to most experts, an average temperature range of 72 to 79 degrees Fahrenheit is the best for almost every typical platy

These fish can tolerate fluctuations in water and temperature, although sudden changes in the water parameters must be considered. But in all cases, try to avoid those dramatic adjustments as much as possible – since they can cause major stress to your beloved pet!

What if I still want to leave the water below that temp range? Some readers may ask. 

We answer that they can be somewhat tolerated – meaning no immediate dangers would arrive. 

Still, remember that long-term health issues can increase dramatically and out of your control! For fish with weaker stamina, low temperature also causes other terrible outcomes (such as premature deaths and lower lifespans). 

Hence, it would be best to tread with more caution and get the temperature precisely right, avoiding those unfortunate consequences!

During summer periods, keeping the water temperature steady is a piece of cake without any supported device. However, for fishkeepers living in places with chilly weather, you may find it almost impossible to make the temperature stay consistent all the time. 

Under those circumstances, we suggest you switch on the house’s heater and increase its setting higher than normal. How can we make sure the heaters are chosen and installed properly? Please tune in to the next section for more tips!

Things to Consider When Choosing and Installing Tank Heaters for Platy Water Temp


aquarium in the dark

In most cases, the heaters are always rated in a unit called Watts – to calculate how powerful your heaters are. The larger the numbers are, the faster it can heat the tank water and keep the temperature 100% consistent!

Large fish tanks will require much greater energy levels to stay warm, meaning you must purchase high-wattage heaters. Fortunately, for smaller tanks, you can save some pennies with less powerful devices that operate slower.

By way of illustration, a typical heater of about 50 watts is more than sufficient for a tank with a 55-gallon capacity. On the other hand, 250-watt heaters should be more suitable for larger tanks with 200 gallons or so. 

This quick summarization will assist you in making better and faster decisions:

  • 50 watts: 55-gallon tanks (maximum)
  • 75 watts: 99-gallon tanks
  • 150 watts: 120-gallon tanks
  • 200 to 250 watts: 200- to 300-gallon tanks

Remembering these numbers is important because high-performance heaters are not always a good thing. Using too-powerful heaters for too-small aquariums might worsen the situation and generate more excessive temperature than needed!

Heater Type

Submersible pumps


Most seasoned fishkeepers like to use submersible heaters – since it’s easy to hide them from plain sight by putting them inside the tank. However, there is one major downside to them, which is the potential of electrical shocks – particularly in aquariums whose water levels are low! 

Within the submersible categories, numerous size options are available, from clip-on small-sized models for single tanks to larger and more powerful ones that easily cover more than 100 gallons in one go. 

At the end of the day, which size you choose should depend on the tank/fishbowl size, as we already mentioned above. (please refer back to the summary chart). 

Ultraviolet Lamps

Compared to their submersible counterparts, ultraviolet lamps are rarer and lag slightly behind in terms of quality. Still, if you are one of those people who want continuous heating without high prices and complex designs like heaters, then these lamps are your best bet!

In essence, they keep the tank’s water temp at a level of your choice on the tank’s top, meaning you don’t have to buy filters and similar devices. 



As we have repeatedly stressed, heaters should always be positioned inside the water, ensuring consistent and appropriate temp without dramatic changes. Hence, it’s necessary to ensure that the tank/fishbowl setup allows flexible control of the heater’s placement. 

Overall, professionals recommend fishkeepers put their heaters at one chosen end of the aquarium/fishbowl to offer even heat throughout the surface area. 

Meanwhile, putting the heaters right in the middle is better for smaller containers (like cups and bowls). Otherwise, the device will be closer to the fish than required, which might cause burns or even fry them if malfunctions occur!

Hooking up the heaters OUTSIDE the tank is also not recommended. Why do we say so? It’s because they might easily get knocked by curious pets (say, your naughty cat) that wonder what is happening beyond the aquarium – especially when you are not looking! 

But of course, if you have customized designs for out-of-the-tank heaters, then there’s no need to worry about such issues. One terrific suggestion is to buy heater guards to protect both the fish and the tank walls from unwanted accidents – whether the heaters are internal or external. 


What is the right platy water temp? Are there any criteria I should pay attention to when choosing tank heaters? This article has answered all those burning questions for you. Keep them in mind, and write to us if you still need support!